Asahi Shimbun: Increasingly, investors in Japan are learning that they can make green by thinking green. Concerns about global warming have spread, as have business operations related to climate change. Although many companies may still cast doubts on whether global warming really exists, they cannot deny the growing popularity of "eco-funds" or the trend among investors to make decisions from an environmental standpoint. In July last year, a 31-year-old investor living in …